Recently, there is extensively used an endoscope whereby organs within a body cavity can be observed by inserting an elongate insertable part into the body cavity and, as required, various curing treatments can be made by using treating tools inserted through a treating tool channel.
There are also suggested various electronic endoscopes (called also electronic scopes) wherein a solid state imaging device such as a charge coupled device (CCD) is used as an imaging means.
Now, in the above mentioned endoscope, there has been conventionally an illuminating light feeding means, as largely divided, wherein a light guide is inserted through the endoscope insertable part and an illuminating light from the light source apparatus is fed to this light guide and wherein a lamp such as a light emitting diode (abbreviated as LED hereinafter) is provided in the tip part of the endoscope and is made to emit a light.
The endoscope having the above mentioned light guide has advantages that the tip part of the insertable part can be made fine, the light emitted from the light source apparatus can be variously changed and the observation with a special wavelength illuminating light, such as an infrared light for an electronic endoscope, is easy.
On the other hand, the endoscope having a lamp in the tip part has advantages that the flexible part connected to the rear end of the above mentioned tip part can be made fine, the light guide will not break and, even if the insertable part is long, it will not become dark.
Now, the endoscope having the light guide and the endoscope having the lamp have been used a respectively separately connected to the light source apparatus and to the power source. Therefore, in case the above mentioned two kinds of endoscopes are to the used, respectively different light source apparatuses and power source will have to be prepared and operated. Thus, the economy and efficiency have been low.
In the publication of a Japanese patent application laid open No. 217327/1985, there is disclosed a technique that a red color LED and blue color LED slightly containing a green component are provided at the tip of an endoscope insertable part. An object image obtained from illuminating lights emitted from these LED's is imaged by a solid state imaging device having a mosaic filter. The output signal of the solid state imaging device is separated into respective color component signals of red, green and blue and then further the color component signals are amplified so that the color characteristics of the reproduced picture image may be uniform.